The Advantages of Obscurity: Charles Darwin's Negative Inference from the Histories of Domestic Breeds

In The Origin of Species, Charles Darwin famously accounted for the lack of fossil evidence in support of species evolution on the grounds that the fossil record is naturally incomplete. This essay examines a similar argument that Darwin applied to his analogy between natural and artificial selection: the scarcity of data about the historical backgrounds of domestic breeds was the natural by-product of an extremely gradual change process. The point was to enhance the ability of the artificial selection analogy to suggest that nature's species had undergone a similar transformation. Darwin did not depend on this negative inference alone, however, for in his writings he included whatever information he could find about the actual histories of particular breeds. A comparison with Darwin's treatment of the fossil record suggests the reasonableness of this combined use of opposite kinds of evidence to establish a single point. The comparison also suggests the unique qualities of negative inference as applied to the breeding analogy.     

Electrophoresis of the venom and haemolymph of the scorpionButhus Judaicus E. S.

Zusammenfassung Die elektrophoretische Analyse des Skorpiongiftes vonButhus judaicus E. S. ergab den Gehalt von mindestens 6 Proteinfraktionen. Drei dieser Fraktionen waren bei pH 8,6 von kathodischer Beweglichkeit und von offenbar höchster Toxizität. Davon völlig verschieden war das elektrophoretische Bild der Eiweisse in der Skorpionhämolymphe.     

Aging of the erythrocyte. III. Cation content

Summary Studies on the main cation content of density-separated bovine erythrocytes showed a progressive decrease in the levels of K⁺ and Mg²⁺ with increasing cell density (and age) accompanied by an increase in the level of Na⁺. The magnitude of net cation loss corresponded to that of red cell volume decrease, but could not account for the total increase in the microviscosity of the erythrocyte interior.     

Aging of the erythrocyte. II. Activities of peroxide-detoxifying enzymes

Summary The activity of glutathione peroxidase decreases and that of catalase does not change during erythrocyte aging, as judged from a comparison of bovine red cell fractions separated by density.We are indebted to Prof. W. Leyko for many stimulating discussions.     

Investigations on the turnover of adrenocortical mitochnodria. VII. Effects of ACTH on the half-life of mitochondria from the zona reticularis of the rat adrenal cortex.

The half-life of mitochondria from the zona reticularis of the rat adrenal was calculated by determining the radioactivity decay curves of the mitochondrial compartment of 3H-thymidine-injected animals, using autoradiographic methods. ACTH was found to enchance significantly the half-life of the organelles.     

J. L. Lagrange's changing approach to the foundations of the calculus of variations

Archive for History of Exact Sciences -     

Aging of the erythrocyte. XV. Isoosmotic lysis times

Summary Isoosmotic lysis times of various density (age) fractions of human, pig and ox erythrocytes in glycerol and ammonium chloride solutions decreased with increasing cell density.I am indebted to Prof. W. Leyko for many stimulating discussions.     

The portraiture of the honourable Robert Boyle,F.R.S.

“To whom is the Consecration of Medal, Stature or even Pyramid more jusly due, than to … the late Illustraious Boyle? … for the happy Improvement of Otto Guericks Magdeburg Exhausterm and for his Profound and Noble Researches into all the abstruser Parts and Recesses of the most useful Philosophy … I have named the Illustrious Boyle, and fix his Trophy here.”

John Evelyn, Numismata, 1697.